Stereolithographic techniques for forming three dimensional polymer structures are know. However, these techniques are primarily directed to layer by layer hardening of a polymeric material using laser irradiation and are not applicable to the production of metallic items/structures which have complex shapes having overhangs/undercuts that require the interposition of supporting arrangements such as scaffolds. Therefore, the need for a technique which enables a metallic three-dimensional structure having a complex shape, to be developed in this layer-by-layer manner, exists.